Relationship between dietary factors and S-Klotho plasma levels in young sedentary healthy adults

•S-Klotho has emerged as important anti-ageing biomarker related to the promotion of health span.•Ethanol intake was directly associated with S-Klotho plasma levels in women.•A pro-inflammatory diet was inversely associated with S-Klotho plasma levels in young adults, being partially mediated by LMI and uric acid level. To study the associations of dietary factors with S-Klotho plasma levels in young adults. We also aimed to study whether body composition and cardiometabolic risk factors affected the association between dietary factors and S-Klotho plasma levels. A total of 139 young adults took part in this study. Dietary factors were measured using a food frequency questionnaire and three non-consecutive 24 h recalls. S-Klotho plasma levels were measured by immunosorbent assay. Body composition was measured by DXA. We observed a direct association of ethanol intake and S-Klotho plasma levels in women. An inverse association was also observed between the dietary inflammatory index (DII) with S-Klotho plasma levels in all sample. No mediation effects of body composition or cardiometabolic risk factors were observed in the relationship between alcohol and S-Klotho plasma levels. Lean mass index (LMI) and uric acid levels mediated the relationship between DII and S-Klotho plasma levels. A pro-inflammatory dietary pattern was inversely associated with S-Klotho plasma levels in young adults, which was partially mediated by LMI and uric acid levels.